Strategies for reducing the dosing interval of orally absorbed drugs rely on changing the release pattern of the drug from the delivery system such that the blood level profile of the drug falls within the therapeutic window over the time of the dosing interval. However, for drugs that exhibit first-pass metabolism, the relationship between extent of absorption and bioavailability is nonlinear thereby leading to reduced bioavailability when drugs are administered at a very low rate into the GI tract. The specific aim is the development of a drug delivery strategy to reduce the oral dosing interval of drugs exhibiting first-pass metabolism while maintaining bioavailability equivalent to the immediate release dosage form. The strategy entails the design and development of a dosage form strategy which will release fractions of the total dose at specified times/sites in the GI tract. In this manner the bioavailability will not be compromised by the decreasing release rate as seen in conventional sustained release dosage forms. Propranolol has been chosen to be the specific test drug to be studied. Propranolol was chosen because the pharmacokinetics of propranolol are reasonably well understood, it exhibits dose dependent bioavailability in the normal therapeutic dosage range and there have been reports in the literature of technology that has been developed for the controlled release of propranolol, for example Inderal-LA, which are not satisfactory with respect to their bioavailability.